#define _CRT_SECURE_NO_WARNINGS
class Solution {
public:
    vector<vector<int>> construct2DArray(vector<int>& original, int m, int n) {
        if (m * n != original.size()) return {};
        vector<vector<int>> ret;
        auto it = original.begin();
        while (it != original.end())
        {
            vector<int> tmp(it, it + n);
            ret.push_back(tmp);
            it += n;
        }
        return ret;


    }
};